1. Field of the Invention
The invention pertains to a telescoping table with a base and at least two slides and a support table, which are guided in linear fashion on the base in a telescoping manner, and with at least two drive devices mounted on the base, one of which is connected by drive means to the first slide only, whereas the second operates cables or lengths of chain, which move the second slide or the second slide plus additional slides as well as the support table.
2. Description of the Related Art
Telescoping tables of this type are used, for example, in high-shelf warehouses to load the shelving compartments with goods an d to remove the s tacked goods again later. The distance by which the telescoping table can extend inward is limited by the width of the aisle between the shelving units; often, however, not only normal but also oversized extensions are required, when, for example, two pallets are to be stored one behind the other in a deep shelf compartment, or when special conditions must be dealt with such as the presence of a fire wall. Although it is possible not only to extend the individual slides and the support table fully to achieve the optimum telescopic extension but also, in principle, to extend them only partially to achieve smaller telescopic extensions, the conventional drive devices of the slides and of the support table are designed in such a way that the end surfaces of the support table and of, for example, the two slides following along after it are so close together when only partially extended that the two slides which support the support table must also enter the shelf compartment. Therefore, with respect to the maximum height of the load which can be accepted, it is necessary to take into account the height not only of the support table itself but also of the slides which guide it.
As a way of eliminating this disadvantage, EP 0,410,286 A2 proposes that the support table and the slides connected to it not be extended in the conventional manner, that is, in a chronologically parallel or synchronous manner; instead, they are to be extended one after the other under the control of locking devices, so that, for example, when the support table is to telescope out only a short distance, the support table moves out first and then the slides which carry it move out, until the desired degree of extension is achieved. The extra complexity associated with the locking devices, however, is unfavorable. The jerky operation of the support table, caused by the acceleration and deceleration of the telescoping components in question, and the limitation on the speed at which the table can be extended under operating conditions of this type are also disadvantageous.
PCT WO 94/04,447 pertains to support forks which are designed to accept containers and discloses another possibility of keeping a large distance between the pick-up fork, which is provided in place of a support table, and the following slide even in cases where the fork is extended only a short distance. Namely, two drive devices, which are guided on the base, are assigned to the slides; one of these drives determines the displacement of the slides, while the other determines the displacement of the support table or support fork with respect to the preceding slide. One of the drive devices acts by way of shiftable gears or a gear boxes with different ratios. Thus, although the support table or support fork can always be extended fully with respect to the slides supporting and guiding it, the mounting of the drive devices, their energy supply lines, and the gear boxes subordinate to them on a slide present considerable difficulties. The transmission of the movement to the support table or support fork by way of any additional slides which might be provided also proves to be highly complicated and susceptible to breakdown.
FR-A-2,709,745 discloses a telescoping tab le, which is equipped with two drive devices, installed on the base, which move the slides and the support table; each of the drive devices drives an endless chain. One of these chains is attached to the first slide, the other to another endless belt, which for its part is attached to an endless belt in the following slide. Thus, although it is possible for the slides to be extended to different degrees in a controlled manner, the use of anchors extending crosswise to the chains to attach them impairs the precision of the control and the drive moments which can be generated to move the slides.